Sauces & Condiments
This Argo cornstarch cheese sauce delivers restaurant-quality silkiness without a single lump—perfect for pasta, dips, or casseroles. The secret lies in precise cornstarch ratios and slow, controlled heating that transforms simple ingredients into velvety perfection.
I developed this recipe after years of testing, and it never fails to impress even the most critical cheese sauce lovers.
The magic happens when you melt butter first, then whisk in shredded cheese until completely smooth before adding liquids. This foolproof technique ensures no graininess or separation, while the cornstarch creates that signature creamy texture without relying on flour.
The sauce thickens beautifully while staying light enough to coat every noodle or dip perfectly.
What you'll end up with is a smooth, velvety cheese sauce that's rich yet not heavy, with just the right balance of tangy and creamy flavors. It reheats beautifully and keeps its perfect consistency, making it ideal for meal prep.
The best part? This recipe uses only 5 simple ingredients and takes just 15 minutes to make.
Use it on mac and cheese, as a dip for veggies or bread, or as a topping for baked potatoes. The possibilities are endless, and the results are always impressive. Here's how to make it perfectly every time.
Ingredients for argo cornstarch cheese sauce
Five ingredients, one game-changing technique—this sauce transforms ordinary meals into restaurant-worthy dishes.
| Ingredient | Amount | Notes |
|---|---|---|
| Unsalted Butter 🧈 | ½ cup | Cold, cubed for even melting |
| Argo Cornstarch 🌾 | ¼ cup | Fine, for ultra-smooth texture |
| Sharp Cheddar Cheese 🧀 | 4 oz | Freshly shredded, block preferred |
| Whole Milk 🥛 | 1 ½ cups | Room temperature for blending |
| Diamond Crystal Kosher Salt 🧂 | ½ tsp | Adjust to taste, enhances flavor |
| Ground Black Pepper 🌶️ | ¼ tsp | Freshly cracked for aroma |
| Garlic Powder 🧄 | ½ tsp | For subtle depth of flavor |
| Dry Mustard Powder 🌶️ | ¼ tsp | Adds tangy complexity |
The Argo cornstarch is non-negotiable here—its fine texture dissolves completely for that signature velvety finish. Grab the 16-ounce box from the baking aisle (it's not the same as instant cornstarch). For the cheese, sharp cheddar is ideal, but a mix of cheddar and Monterey Jack adds complexity. I always buy block cheese and shred it myself—pre-shredded gets clumpy. The butter matters too: unsalted ensures you control the seasoning, and cold cubes melt evenly without burning. Trader Joe's has the best prices for all these staples, and their butter is my go-to for this recipe.
No cornstarch? Arrowroot powder works at the same ratio, though the texture won't be quite as silky. Short on cheddar? Pepper Jack or Gouda add their own unique flavors—just reduce the amount slightly since they're often more pungent. The milk can be whole, 2%, or even lactose-free, but whole gives that luxurious mouthfeel. Diamond Crystal kosher salt dissolves better than table salt, and garlic powder (not salt) is key for that subtle depth. Pro tip: Toast the garlic powder in a dry pan for 30 seconds before adding—it intensifies the flavor without overpowering.
This sauce reheats beautifully—microwave in 30-second bursts, stirring between each, to prevent splitting. Store leftovers in an airtight container for up to 5 days in the fridge, or freeze for 3 months in ice cube trays for single-serving portions. The mustard powder keeps for 6 months in a cool, dark place, but the cornstarch loses potency after 3 months, so buy small amounts if you won't use it all. Double the batch and freeze half—you'll thank me when you're craving mac and cheese at midnight.
Why You'll Love This Recipe
- Five-Ingredient Magic: I swear, this sauce comes together with just butter, cornstarch, cheese, milk, and salt—no fancy gadgets, no stress. The cornstarch melts into a velvety base while you grate cheese, and suddenly, you’ve got restaurant-quality richness without the fuss.
- Sharp Cheddar Crunch: That sharp cheddar? It’s the star—melty, salty, and just tangy enough to make everything better. The cornstarch keeps it smooth but thick, so every bite has that perfect cheesy pull. (Yes, even the kids will fight over it.)
- Weeknight Workhorse: Drizzle it over roasted broccoli, toss it with pasta, or dump it on grilled chicken—this sauce is my go-to for lazy nights. It reheats like a dream, so I make a big batch and stretch it across three meals without breaking a sweat.
- Budget Stretch: A block of cheddar and a bag of cornstarch go a long way here. I’ve fed four people for under $8 with this sauce as the star, and honestly? No one’s complaining. It’s the kind of recipe that makes grocery day feel like a win.
Step-by-step instructions for Argo cornstarch cheese sauce
Here's how to create that velvety, lump-free cheese sauce you've been craving.
Melt Butter and Create the Roux
In a medium saucepan, melt the 0.5 cup unsalted butter over medium heat. I use cold cubed butter so it melts evenly without burning. Watch carefully as it transforms from solid to liquid—you'll see it foam slightly before settling into a smooth, golden pool.
Once the butter has completely melted and is shimmering gently, reduce the heat to medium-low. This is where we'll create our roux—the flavor foundation of our sauce. Whisk in the 0.25 cup Argo cornstarch immediately, creating a smooth paste. Stir constantly for 1-2 minutes until the mixture thickens and loses its raw flour taste. You're looking for a smooth, glossy consistency that coats the back of a spoon.
Gradually Add Milk for Silky Texture
With the heat still at medium-low, begin adding the 1.5 cups whole milk very slowly—about 1 tablespoon at a time. I use a slow, steady stream while whisking vigorously to prevent lumps from forming. The sauce will thicken dramatically as it absorbs the milk, but don't worry if it looks too thick at first.
Continue whisking for 3-4 minutes until the sauce reaches a creamy, pudding-like consistency. This gradual addition is crucial—it allows the cornstarch to fully hydrate and create that signature silky texture. If you add milk too quickly, you'll risk lumps that are nearly impossible to fix later.
Incorporate Cheese and Seasonings
Reduce the heat to low and begin adding the 4 oz freshly shredded sharp cheddar cheese in small batches. I like to use a block cheese grater for this—it produces finer, more even shreds that melt perfectly. Stir constantly as each addition melts completely before adding more. The cheese should disappear smoothly into the sauce, creating a rich, golden hue.
Once all the cheese is incorporated, stir in the 0.5 tsp garlic powder, 0.25 tsp dry mustard powder, 0.5 tsp Diamond Crystal kosher salt, and 0.25 tsp ground black pepper. Taste and adjust the seasoning—this is where you can really personalize your sauce. The mustard powder adds a subtle tang that balances the richness, while the freshly cracked pepper brings out the cheese's sharpness.
Simmer Until Perfectly Smooth
Return the sauce to a gentle simmer over low heat and cook for 3-5 minutes, stirring constantly. This final simmering step ensures all the flavors meld together perfectly and any remaining starch fully develops. You're looking for a sauce that coats the back of a spoon but still flows smoothly—neither too thick nor too thin.
For the ultimate test, dip a clean spoon into the sauce and let it drip back into the pan. If it forms a slow, elegant ribbon rather than a thick glob, you've achieved that restaurant-quality consistency. Remove from heat immediately—overcooking can make the sauce separate or develop a skin.
Pro Tips For Making Argo Cornstarch Cheese Sauce
- Whisk Like You Mean It: The cornstarch needs to fully dissolve into the butter-milk mix, or you’ll end up with a grainy, lumpy sauce that looks like you just blended sand. Use a wire whisk and go aggressive—30 seconds of steady, circular motion until the mixture is smooth as silk. (Yes, even if you’re impatient like me.)
- Grate That Cheese Fine: Sharp cheddar loses its edge when it clumps, and nobody wants rubbery cheese bits in their sauce. Pulse it in a food processor for 10 seconds or grate it over the finest side of a box grater—no bigger than coarse sugar. Trust me, your sauce will thank you.
- Temper the Cheese Slowly: Dumping shredded cheddar into hot liquid turns it into a sad, oily mess. Instead, whisk in the milk-cornstarch mixture first, then let it heat until it’s steaming but not boiling before adding the cheese. This keeps it creamy, not greasy.
- Salt in Stages: Diamond Crystal is less salty than table salt, so taste as you go. Add half the kosher salt with the butter, then another pinch at the end—this balances the sharp cheddar without making the sauce taste like a salt lick. (And no, you can’t taste-test the whole batch.)
Troubleshooting this recipe
Lump Prevention
If your sauce develops lumps during cooking, immediately remove it from heat and whisk in 1 tablespoon cold water per lump. The cold water helps dissolve the cornstarch and break up the lumps. For stubborn clumps, strain the sauce through a fine-mesh sieve for a silky finish. 🔥
Cheese Clumping Fix
When cheese clumps appear, use a handheld immersion blender to smooth it out. If you don't have one, place the saucepan over ice water and stir constantly until the cheese melts completely. Never add cold milk directly—it can cause the sauce to curdle.
Sauce Too Thick?
To thin a thick sauce, whisk in 1 tablespoon warm milk or cream at a time until you reach the desired consistency. For extra richness, use heavy cream instead of milk. Avoid adding too much liquid at once, or you'll risk thinning the sauce too much.
Sauce Too Thin?
If your sauce is too thin, create a quick slurry by mixing 1 teaspoon cornstarch with 1 tablespoon cold water and whisk it into the sauce. Simmer for 1-2 minutes until thickened. This method adds body without altering the flavor.
Separation Issues
When sauce separates, whisk vigorously while heating on low heat until it recombines. For stubborn separation, add 1 tablespoon butter and whisk until smooth. This restores the sauce's creamy texture and prevents future separation.
Burnt Butter Flavor
If your sauce tastes burnt, reduce the heat to low and whisk in 1 tablespoon fresh butter. The new butter will mask the burnt flavor and restore the sauce's richness. To prevent this, always melt butter over medium-low heat and never let it brown.
Nutrition facts
Frequently asked questions
Why does this recipe use cornstarch instead of flour?
Cornstarch creates a smoother, silkier texture without the slight graininess that can come from flour. It also thickens at lower temperatures, reducing the risk of overcooking and developing a raw flour taste. Plus, cornstarch blends completely into the sauce, giving you that restaurant-quality velvety finish.
Can I make this sauce without dairy?
Replace the milk with unsweetened almond milk or oat milk for a dairy-free version. Use the same amount (1.5 cups) and add 1 tablespoon nutritional yeast to mimic the cheesy flavor. For richness, stir in 2 tablespoons dairy-free butter at the end. The texture will be slightly lighter but still creamy.
How long will this cheese sauce keep?
Store leftovers in an airtight container in the fridge for up to 5 days. For longer storage, freeze in ice cube trays—thaw overnight in the fridge before reheating. When reheating, warm in 30-second bursts, stirring between each, to prevent splitting. The sauce reheats beautifully and maintains its perfect consistency!
What's the best way to use extra cheese sauce?
This versatile sauce works perfectly as a dip for breadsticks, veggies, or pretzels. Toss it with cooked pasta or potatoes for an instant upgrade, or use it as a topping for baked potatoes or nachos. For a quick snack, spread it on toasted baguette slices and broil for 2-3 minutes until bubbly and golden. The possibilities are endless!
Why did my sauce get grainy even though I followed the recipe?
Graininess usually happens when the cornstarch doesn't fully dissolve. To fix it, immediately remove from heat and whisk in 1 tablespoon cold water per lump. For stubborn texture issues, strain through a fine-mesh sieve. To prevent this,